Mold for the manufacture of electrical switchboards



(No Model.)

J. B. LYON. I MOLD FOR THE MANUFACTURE OF ELEGTRIGAL SWITGHB'OARDS. ANo. 479,891. Patented Aug. 2,1892.

JOHN B. LYON, OF BROOKLYN, NEW YORK.

MOLD FOR THE MANUFACTURE OF ELECTRICAL SWITCHBOARDS.

SPECIFICATION forming part of Letters Patent No. 479,891, dated August2, 1892.

Application filed January 19, 1891. Renewed June 16, 1892. Serial No.436,993. (No model.)

To all whom it may concern:

Be it known that LJOHN B. LYON, a citizen of the United States, residingin Brooklyn, county of Kings, and State of New York, have inventedcertain new and useful Improvements in Molds for the Manufacture ofElectrical Switchboards, of which the followingis a specification.

This invention has reference to electrical switchboards, and relatesparticularly to the switchboards used in telephonic and telegraphicsystems.

The object of the invention is to simplify and cheapen the manufactureof switchboards; and it consists in the apparatus herein after describedfor manufacturing the cards or sections containing the sockets of theswitchboards.

The invention consists of the details of construction, which will behereinafter described and claimed.

In the accompanying drawings, Figure 1 represents a perspective view ofa single card or section of which the switchboard is built up. Fig. 2 isa view of one of the contactpieces or electrodes. Fig. 3 is a plan ofthe mold containing the contact-pieces and showing their appearance andlocation before the rubber is applied. Figs. 4, 5, and 6 are perspectiveviews of sections of the mold. Fig. 7 is a transverse section of themold when all the parts are adjusted and at work; and Fig. 8 is anenlarged detail of the mold, illustrating the manner of settingorsecuring the contacts before the rubber is applied.

The finished card shown in Fig. 1 consists of a hard-rubber rectangularstrip containing a plurality (usually ten) of sockets or cavitiesextending from one edge of the card through and past the middle of thesame. The sockets have four sides converging toward the interior and areextended through the card to the rear edge by two tubular passages. Ineach socket there are secured two metallic contact-pieces or electrodesa. These are placed opposite each other and consist of a rectangularportion and a tubular portion, the former being located in the socketproper and the latter extending through the respect ive tubular passagesof the socket. It has been found exceedingly difficult to manufac turethis article, the difficulty arising mainly in the supporting of theelectrodes while the rubber is being applied and in the application ofthe rubber, so that shrinkage will not take place at particularlocations. In order to explain my improved method for overcoming thesedifficulties, I refer now to Figs. 3,4, 5, 6, and 7, in which Brepresents a metallic frame or plate of a little greater thickness thanthe finished card and made of solid tin or an alloy of tin or othermetal covered with tin or an alloy of tin. It has a central opening,constituting three compartments b, b, and 11 The central opening b is ofgeneral rectangular shape and is the place where the card is formed. Theopenings (9 and 19 receive two removable sections B B respectively. Theends of the sections B B are beveled or inclined to fit the ends of theopenings b If, respectively. They are of. the same thickness andmaterial as the plate B. The section B is provided along its shorterside with ten wedge-shaped pegs or mandrels 12 which correspond in sizeand shape with the ten sockets in the cards. These mandrels, when thesection B is in place in the plate B, project into the rectangular spaceZ). The section B is provided on its shorter side with a series of shortpins or mandrels b arranged in pairs, one pair for each socket in thecard A. When the section B is in place in the plate B, the pins 6project into the opening 17, and each pair of them stands opposite oneof the mandrels b of the section B.

The mold having now been described, I will proceed to explain the mannerof handling it in the manufacture of these cards. The section B,detached, is first taken and each mandrel b fitted with two of theelectrodes a. They are adjusted to the opposite sides of the mandrels inthe manner shown in Fig. 8, and between every two mandrels, after theelectrodes have been adjusted, a wedge c is driven in to force theelectrodes tightly upon the mandrels and to hold them temporarilypending the final binding of hard rubber. Vt hen all of the mandrels onthe section B have been fitted with the electrodes, as shown in Fig. 7,the section B is then connected with the electrodes by inserting thepins 1) into the open ends of the tubular portions of the electrodes,respectively. The two sections B and B are then inserted into theirproper places in the plate B, thereby rigidly supporting and holding theelectrodes in proper relation to one another. To hold and force theterminal electrodes tightly upon the mandrels, a wedge is then driven inbetween each one and the frame B. The next step in the method is toapply the rubber. It is to be understood that the plates and all theparts of the mold are kept in a heated condition. A sheet of soft rubberis placed upon one side of the electrodes, entirely filling one side ofthe opening I). Then a sheet of tinfoil (represented byt in Fig. 7,) isplaced over the rubber. After this a metal plate 29, provided with alongitudinal groove 19' is placed over the foil, so that the groove willextend along the edge of the rubber sheet or of the opening 1) adjacentto the base of the mandrels. Then a plate q of peculiar shape is placedagainst the opposite side of the electrodes to sustain them and pressureis put upon the plate 19.

shown in the lower half of the mold in Fig. 7, and the plate when inposition occupies the space filled by this rubber. The rubber being softis forced into and through the interstices between the electrodes andinto the groove 19'. The function of the groove 19 is to form areservoir of rubber, which, when the rubber shrinks in the vuloanizingprocess, as it invariably does, will supply a sufficiency and insureabout and around the base of the mandrels a complete filling of the moldand a perfect card. When the rubber has been applied to one side, theplate q is removed and a sheet of rubber and another of foil are appliedto the other side. Then, after the adjustment of the plate 13 pressureis again applied and the molding is complete. The next operation is thatof vulcanizing, which is done while the card is yet in the mold. Thefunction of the foil is to seal the sides of the mold while it isundergoing the vulcanizing process. WVhile cooling after vulcanizing therubber shrinks and tends to cause malformation of the card at the baseof the mandrels, (which is the exposed portion in the switchboard.) Thisis prevented, however, by the bead of rubber formed in the groove 1),which is drawn down The cross-section of this plate (1 is of the sameshape as the rubber into the body of the card and supplies thedeficiency in its neighborhood caused by shrinkage. The foil beingflexible, the rubber in the bead which sticks to it draws it in when theshrinking takes place. After vulcanizing the card is taken from the moldand trued up by cutting and grinding.

Great difliculty has been encountered in the manufacture of these cards,principally occurring in temporarily supporting the electrodes beforethe rubber was applied and in the shrinking of the rubber whilevulcanizing. The use of the wedges entirely overcomes the formerdifiiculty and the groove 19' in the plate overcomes the latter. Themold itself has been a great source of trouble and expense.

The separable feature of the mold is a good one, in that it facilitatesthe adjustment of the electrodes.

Having thus described my invention, I claim 1. In a mold for formingcards or sections of electrical switchboards, the combination of aframe, parts of which are removable, with devices for supporting thecontact-pieces of the section, said devices being attached to or carriedby the removable parts of the frame, substantially as described.

2. The combination, with the frame 13,, B, and B of the plates 1919provided with the groove 19', for the purpose set forth.

3. The combination, with a mold provided with removable sections, suchas the plates 19 p, of a removable plate or plug shaped to fit a portionof the mold, for the purpose set forth.

4. A mold for forming cards or sections of electrical switchboards,consisting of a plate provided with a plurality of mandrels arranged ina row, a second plate provided with a plurality of supporting-pins, anda frame adapted to hold the two plates and itself, forming part of themold,substantially as described.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

JOHN B. LYON.

Witnesses:

FRANK S. OBER, WM. A. RosENBAUM.

